We recently upgraded our GCC tool set to 3.2.1 from 2.95.2. I have written a C++ module
to parse STDF binary test data files and return the data in python objects. With the older
compiler, including G++, the 'staticforward' and 'statichere' macros functioned without incident;
I was able to link python by specifying the linker as (CXX). The new G++ (3.2.1) bails on compilation,
complaining about re-definition of the static vars. Without posting the whole content of
the module, I was able to work around it in a manner similar to the following examples,
which can be compiled standalone to demo the problem. You don't need extern "C" in
these examples. If any python guru has a more elegant workaround than the following,
please let me know.
---- CUT BROKEN ----
/* Do nothing demo of GCC vs. G++ and Python. This works
with GCC, but G++ won't compile it. G++ bails on the
redefinition of static vars. MR I Have to use G++ to
link Python, because my python module is written
in C++. The older G++ (2.95.2) did not have a problem
with this. */
#include <stdio.h>
/* Python predefines some macros and types like these */
#define staticforward static
#define statichere static
/* Define an arbitrary structure type (Like PyMethodDef) */
typedef struct ADef {
int dummy;
void (*af)(int i);
}ADef;
/* Pre-declare a static array because we need to refer to
it, prior to its definition. Similar to Python's method arrays */
static ADef sarr[2];
/* Create some void funcs which refer to the sarr */
static void bfunc(int i)
{
printf("bfunc: sarr[%d] dummy is %d\n",i,sarr[i].dummy);
}
static void cfunc(int i)
{
printf("cfunc: sarr[%d] dummy is %d\n",i,sarr[i].dummy);
}
/* Define the previously declared static array
including the funcs in the definition. */
statichere ADef sarr[2] = {
{ 12, bfunc },
{ 24, cfunc }
};
main(int argc, char *argv[])
{
sarr[0].af(1);
sarr[1].af(0);
}
---- CUT END BROKEN ----
---- CUT FIXED ----
/*
Do nothing demo of GCC vs. G++ and Python. This works
with G++ and hacks around the problem at run time at the cost
of an additional static ptr. I turns out Python has to
call my module's init() process anyway.
*/
#include <stdio.h>
/* An arbitrary structure */
typedef struct ADef {
int dummy;
void (*af)(int i);
}ADef;
/* Pre-declare a pointer to a static array, which will
be assigned at runtime. */
static ADef *sarr_ptr;
/* Create some void funcs which refer to the sarr */
static void bfunc(int i)
{
printf("bfunc: sarr[%d] dummy is %d\n",i,sarr_ptr[i].dummy);
}
static void cfunc(int i)
{
printf("cfunc: sarr[%d] dummy is %d\n",i,sarr_ptr[i].dummy);
}
/* Define the previously declared static array
including the funcs in the definition. */
static ADef sarr[2] = {
{ 12, bfunc },
{ 24, cfunc }
};
main(int argc, char *argv[])
{
/* In the python module's initmodulename() function,
I added lines similar to this line for the Obj method arrays etc. */
sarr_ptr = sarr;
/**/
sarr[0].af(1);
sarr[1].af(0);
}
---- CUT END FIXED -----
Is this solution the proper one? If not, are there any switches etc. I should use with
G++ to get it to act properly.
Regards,
M. Riendeau
-
Michael H. Riendeau
Staff Test Engineer
Analog Devices ATE Products Group
http://www.analog.c <http://www.analog.com> om
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